The objective of this research is to determine optimal strategies for the total chemical and enzymatic synthesis of bihelical deoxyribopolynucleotides of specific nucleotide sequence. The primary goal is the completion of a computer program DINASYN which generates, evaluates, selects, and schedules the activities required to synthesize any given DNA molecule. In order to achieve this goal the following specific methods and steps will be used: 1. Systems analysis of the complete DNA chemical synthesis problem. 2. Mathematical modeling of the reaction, separation, and analysis steps in DNA synthesis. 3. Optimization via dynamic programming to select the best synthesis paths. 4. Scheduling, by the critical path method, the various activities in the synthesis plan. 5. Testing of the program on the completed alanine gene synthesis and on the current tyrosine tRNA suppressor gene synthesis.